The present invention relates generally to systems and methods for measuring angular deviation in a transparency, and more particularly to system and method for accurately measuring angular deviation in a transparency utilizing a single collimated light beam.
Existing systems and methods for measuring angular deviation in transparencies, and more particularly in windscreens for aircraft may be fairly exemplified by U.S. Pat. No. 4,249,823 to Task, U.S. Pat. No. 4,377,341 to Task et al, U.S. Pat. No. 4,398,822 to Task, and co-pending application Ser. No. 07/374,121 (filed Jun. 23, 1989) by Task, the teachings and background material Presented or referenced therein being incorporated herein by reference. In these references, the intersection of a line image (either a cross-hair or "L" target pattern) is utilized with a linear detector such as a one dimensional charge coupled device array to measure angular deviation. As a consequence, a small but measurable offset exists between the portion of windscreen intended for examination and the portion actually measured.
The invention solves or substantially reduces in critical importance shortcomings in the prior art as just described by Providing system and method for measuring angular deviation of a transparency unaffected by errors resulting from lateral displacement of measurement position. The invention includes a large diameter collimated light source and an angle sensing receiver system with a small diameter aperture to measure the angular deviation caused by a transparency placed in the optical Path between the collimated light source and the receiver system.
It is a principal object of the invention to provide system and method for measuring angular deviation in a transparency.
It is a further object of the invention to provide an angular deviation measurement system and method utilizing a single collimated light beam.
It is yet another object of the invention to provide system and method for accurately measuring angular deviation in a transparency wherein correction for offsets in the measurement location are not required.
These and other objects of the invention will become apparent as a detailed description of representative embodiments proceeds.